|
%I #14 Nov 26 2021 07:32:05
%S 11,26,36,48,50,60,72,74,88,102,104,120,122,124,138,152,154,156,168,
%T 170,184,202,204,220,222,224,240,242,244,258,272,274,276,290,292,306,
%U 324,326,328,348,350,370,372,374,390,392,394,396,408,410,420,432,434,456,480,482,508,510,512,514,516,518,520,534,536,556,558,560,576,596,598,600,602,604
%N Add to 2n+1 the next three primes > 2n+1.
%C Bisection of A174221.
%H Michael De Vlieger, <a href="/A174223/b174223.txt">Table of n, a(n) for n = 0..10000</a>
%t Array[Total@ Prepend[NextPrime[#, {1, 2, 3}], #] &[2 # + 1] &, 74, 0] (* _Michael De Vlieger_, Oct 25 2017 *)
%o (PARI) A174223(n)=sum(c=1, 3, n=nextprime(n+1),n=2*n+1) \\ _M. F. Hasler_, Oct 25 2017
%o (Python)
%o from sympy import nextprime
%o def a(n):
%o base = 2*n + 1
%o p1 = nextprime(base)
%o p2 = nextprime(p1)
%o p3 = nextprime(p2)
%o return base + p1 + p2 + p3
%o print([a(n) for n in range(74)]) # _Michael S. Branicky_, Nov 26 2021
%Y Cf. A174221, A193230.
%K nonn
%O 0,1
%A _N. J. A. Sloane_, Nov 26 2010
|
